Method and apparatus for making multicomponent nonwoven fabric



Dec. 31, 1968 E. BOBKOWICZ I 3,419,451

METHOD AND APPARATUS FOR MAKING MULTICOMPONENT NONWOVEN FABRIC FiledApril 23, 1965 O II I 2/ W W 6 a we Bl I 6 L \\VI;: ;ir -9 10,21 l8 I920 C) O Q F/GQ/ l 20 F [G 2 INVENTOR.

EMILIAN BOBKOWICZ United States Patent 3,419,451 METHOD AND APPARATUSFOR MAKING MULTICOMPONENT NONWOVEN FABRIC Emilian Bobkowicz, 1155Dorchester Blvd., W. Suite 905, Montreal 2, Quebec, Canada Filed Apr.23, 1965, Ser. No. 450,444 14 Claims. (Cl. 156-161) ABSTRACT OF THEDISCLOSURE Multicomponent nonwoven fabric is produced by extruding froma die a curtain of warp resin filaments which are then stretched toprovide molecular orientation, s multaneously helically and continuouslywinding by means of a rotating frame a plurality of weft yarns aroundthese warp filaments, which weft yarns, in order to achieve regularspacing, first pass in the notches of serrated strips running along theedges of said curtain of warp filaments, and lamination andconsolidation of the obtained warp-Weft construction are effected by apair of pick-up pressure rolls which are driven at a higher speed thanthe extrusion rate of the warp filaments and thus also accomplish thestretching and resulting molecular orientation of the latter.

This invention relates to improvements in the manufacture of nonwoventextile webs.

More particularly, it relates to a novel method and apparatus for makingmulticomponent nonwoven fabrics through lamination and consolidation ofa curtain of extruded and oriented resinous warp filaments contactedwith suitable weft yarns helically wound around said curtain and,possibly, with additional superimposed webs of staple fibers.

In the hitherto known methods for the manufacture of non-woven fabricsit was necessary to apply a thermoplastic bonding agent in solvent,solution, powder or staple fiber form. This resulted in the requirementthat the material be dried and the resin, serving as the bonding agent,be heat-softened and then cured or coagulated by cooling, before thefinal lamination and consolidation of the nonwoven web could take place.Consequently, these production methods are rather laborious, complex andrelatively slow, and involve economical as well as technologicallimitations.

Applicants Canadian Patent No. 684,091 of Apr. 14, 1964, discloses animproved method and apparatus for producing nonwoven textile webs. Iteliminates some of the drawbacks of conventional processes mentionedabove. However, according to this patent it is still necessary that theyarns which constitute the warp layer and which may or may not comprisea thermoplastic bonding agent, be separately prefabricated.

Also, according to said patent, the web formed of superimposed warp andweft yarns must be heated to activate the bonding agent, before it canbe consolidated and laminated.

The first requirement that the warp yarns be prefabricated is ratherinconvenient because it necessitates a separate production set-upequipped to manufacture warp yarns intended to be used in the process.This also increases the cost of the resulting fabric.

The second requirement of applying heat to the warp and weft yarns alsohas its disadvantages since special care must be taken not to dam-age byheat the staple fibers in said yarns. Moreover, this constitutes alimiting factor in respect of the selection of the thermoplastic bondingagents; only those which have a lower melting point than the employedstaple fibers can be used.

3,419,451 Patented Dec. 31, 1968 The present invention eliminates theabove mentioned inconveniences and limitations and enables to producenonwoven fabrics in one step, without using separately maufactured warpyarns and without applying heat prior to lamination and consolidation.

It is therefore an object of the instant invention to provide a methodand an apparatus for making nonwoven webs in a simple and eflicientmanner without using prefabricated warp yarns.

A further object of the invention is to provide a one step method andapparatus for manufacturing nonwoven fabrics without application of heatto the warps and Wefts prior to their lamination and consolidation.

A still further object of the invention is to provide a method of makingnonwoven textile webs wherein any extrudable resin may be employed toform the warp layer.

Other objects and advantages of the invention will be apparent from thefollowing more detailed description of the invention,

In general terms, this invention is an improvement of that disclosed andclaimed in applicants Canadian Patent No. 684,091 mentioned above.However, instead of using prefabricated warp yarns, there is nowemployed a layer or curtain of directly extruded and oriented warpfilaments. While still tacky, these filaments are brought into contactwith weft yarns which are helically and continuously wound around themso as to form a weft layer. The obtained composite web is consolidatedand laminated by a pair of pressure rolls which are preferably cooled.The rolls are also driven at a higher speed than the rate of resinextrusion in order to achieve the desired axial orientation of theextruded filaments.

To ensure proper spacing and controlled forwarding of the weft yarnlayer, in step with the inner filament warp layer, a prefabricatedcontinuous strip of material, serrated on its outer edge, is conveyed oneach side of the Warp layer. In this Way, the weft yarns enter into theconsecutive notches of the serrated strips, while being wound around thewarp layer, and are thereby evenly distributed and forwarded towards thecooled laminating rolls. The entire combination, including the serratedstrips, is then compressed and consolidated by said rolls into a readynonwoven fabric wherein the serrated strips form a strong inside-bondedside-edge.

In addition, one or two fiberwebs with parallel or randomly arrangedfibers may be superimposed upon the warp-weft construction prior to itslamination and consolidation and while the warp filaments are still inplastic condition. The obtained composite web is then passed through thenip of cooled pressure rolls where the material is consolidated bycompression and coagulation into a multicomponent nonwoven fabriccomprising a strong inside layer of warp and weft yarns and an outsidetexturizing layer of a web of staple fibers.

Summarizing, therefore, the method of the instant invention comprises:

extruding a curtain of resinous warp filaments;

stretching said filaments to cause proper orientation of the resinmolecules;

helically winding around said curtain of warp filaments a layer ofproperly spaced weft yarns so that the latter will contact saidfilaments while they are still in plastic condition;

if desired, superimposing upon the obtained warp-weft construction, onat least one side thereof, a web of staple fibers; and

laminating and consolidating the so produced multicomponent structure.

The apparatus, object of the instant invention, comprises a combinationadapted to carry out the above described method.

Thus, it may comprise: an extruder for extruding a curtain of resinouswarp filaments; a pair of pressure rolls positioned below said extruderand adapted to take-up, compress and consolidate the composite structureof which the extruded warp filaments form the middle layer; means fordriving said rolls at a higher speed than the rate of filament extrusionto cause proper orientation of the filament resin molecules; means onboth sides of the extruder for forwarding strips of material withserrated outer edges at each side of the filament curtain; and means forhelically winding around said warp filaments and serrated strips aplurality of weft yarns so that they will enter into the consecutivenotches of the serrated strips and thereby Will be evenly spaced andforwarded, together with the filament warp yarns, towards theconsolidating pressure rolls.

Moreover, there may be provided, on at least one side of the pressurerolls, means for forwarding a staple fiberweb towards the nip of saidrolls so that it will superimpose the original warp-weft constructionand will be laminated and consolidated therewith.

Finally, there will usually be provided means for cooling the pressurerolls to enhance the coagulation of the resinous material during thecompression operation.

Essentially, however, the apparatus will comprise, in combination:

means for extruding a curtain of resinous warp filaments downwardlyalong a constructional path;

weft layer means close to said constructional path for helically windinga plurality of continuous and proper- 1y spaced weft yarns around saidwarp yarn curtain, to form a multicomponent warp-weft construction;

if desired, means for superimposing upon said warp-weft construction, onat least one side thereof, a web of stable fibers; and

a pair of pick-up pressure rolls at the bottom of said constructionalpath, driven at a higher speed than the extrusion rate of the warpfilaments so as to stretch said filaments in order to cause properorientation of the resin molecules, said rolls also being adapted tolaminate and consolidate the obtained nonwoven construction.

The invention will now be described in greater detail with reference tothe appended drawings in which:

FIG. 1 is a vertical side view of the apparatus according to the presentinvention with some parts shown in section;

FIG. 2 is a vertical front view of the lower portion of the apparatusaccording to this invention with some portions also shown in section;and

FIG. 3 is a section view through line BB of FIG. 1.

As shown in the drawings, there is provided according to the inventionan extrusion apparatus having an extrusion barrel 1 projecting throughthe upper portion of a circular frame 2 which is rotatably mounted bymeans of bearings 4 on a frame 3 and driven by pulley 5. This circularframe 2 has at its lower end a plurality of compartments for carrying aplurality of yarn packages 6 pivotally mounted on shafts 7.

The extrusion die 13, at the bottom of barrel 1, comprises a pluralityof aligned orifices 14 (see FIG. 3) through which the warp filamentyarns 15 are extruded, between downwardly extending plates 11 and 12,towards pick-up laminating rolls 16 and 17.

At the same time, serrated strips 21 are unwound from supply rolls 22and are guided through channels 23 on both sides of the extruder barrel1 and then through channels 24 and 25 on both sides of the extruder head13. These strips are thus conveyed at each side of the extruded filamentcurtain towards the pick-up laminating rolls 16 and 17.

Moreover, while frame 2 is rotated, the yarn ends from packages 6 arethreaded through holes 8 and assembled in a yarn spacing and layingmember 139 Which they are helically wound around the plates 11 and 12bound by the serrated strips 21, in such a manner that the resultingweft yarns 10 enter into the subsequent notches of said strips 21 andform a regularly spaced weft yarn layer around the curtain of extrudedwarp filaments 15.

The so formed construction may be laminated as such or additionallysuperimposed with fiber webs 18 and/or 19 and then subjected to pressureand cooling by passage through rolls 16 and 17 which are preferablychilled from the inside. The obtained finished multicomponent nonwovenfabric 20 can be wound on a commercial fabric roll 26 of suitable size.

The apparatus of the invention therefore comprises: an extruder with anextrusion barrel 1 and an extrusion die 13 adapted to extrude a curtainof filaments 15; a pair of plates 11, 12 positioned about said extrusiondie, extending downwardly thereof and having guiding channels 24, 25 forthe serrated strips 22, said plates being so shaped as to enable windingof weft yarns 10 around their edges and to hold said weft yarns inposition until they are picked-up by pressure rolls 16 and 17; supplyrolls 22 and guiding channels 23 at each side of the extrusion barrel 1for conveying the serrated strips 21 before they enter the guidingchannels 24, 25; a rotatable frame 2 around said extruder withcompartments carrying a plurrality of yarn packages 6 pivotally mountedon shafts 7 and a spacing and laying member 9 for forming a properlyspaced layer of weft yarns 10 helically wound around the side edges ofthe plates 11 and 12 as well as around the serrated strips 21 and thecurtain of warp filaments 15; and a pair of pressure rolls 16, 17 forlaminating and consolidating the formed warp-weft structure, bound bythe serrated strips 21, to form a nonwoven fabric.

The apparatus may also comprise means (not shown) for superimposing uponthis initial structure a pair of fibrous webs 18 and 19 of any desiredquality and design just prior to lamination and consolidation by rolls16, 17.

Finally, the apparatus will also be provided with means for driving androtating frame 2; means for chilling the rolls 16, 17; means for drivingsaid rolls 16, 17 at a higher speed than the extrusion rate of filaments15; an output roller 26; as well as any other instrument or devicerequired for a good performance or control of said apparatus.

The operation of the apparatus enables to carry out the novel method ofthe instant invention and comprises; extruding through the alignedorifices 14 of the extrusion die 13 a curtain of warp filaments 15;picking-up these filaments by the rolls 16, 17 which are driven at sucha speed as to effect on said filaments a substantial drawing action tocause an adequate orientation of the resin molecules; at the same timeconveying through channels 23 and 24, 25 the serrated strips 21 andleading them, one at each side of the filament curtain, towards saidpressure rolls 16, 17 by which they are picked-up and laminated togetherwith the filaments 15; helically winding and properly spacing weft yarns10 around the curtain of filaments 15 through the use of the rotatingframe 2, the spacing and laying member 9, the plates 11 and 12 and theserrated strips 21; and laminating as well as consolidating the wholecombination by cooled pressure rolls 16, 17, if desired, together withsuperimposed fibrous webs 18 and/or 19.

Although any extrudable resin may be used for the warp filaments 15, itis preferred to utilize thermoplastic materials for this purpose.

Furthermore, it is preferable to use thermoplastic serrated strips 21.

As weft yarns 10, it is preferred to employ staple fiber yarns.

Finally, the fi'berwebs 18 and 19 may be made of any suitable staplefibers with parallel or random arrangement of the fibers.

As is evident from the above, the invention enables to produce nonwovenwebs in a simple and efficient manner, with any desired fibrous textureand Without use of prefabricated warp yarns or application of heat foractivating the bonding agent.

The resulting material may therefore be very similar to the usual wovenfabric; but the expensive weaving operation has, of course, beeneliminated. This substantially reduces the cost of the finished product.

It should also be understood that the invention is not limited to thespecifically described and illustrated embodiments and manymodifications evident to those skilled in the art can be carried outwithout departing from the spirit and scope of the invention as definedin the following claims.

I claim:

1. Method for making a multicomponent nonwoven fabric comprising:

(a) extruding from a suitable extrusion die, provided with a pluralityof aligned orifices, a curtain of warp resin filaments;

(b) stretching said filaments to cause proper orientation of the resinmolecules;

(c) conveying a narrow strip with a serrated outer edge at each side ofthe curtain of warp filaments;

(d) helically and continuously winding around said curtain of warpfilaments, bound by the serrated strips, a layer of weft yarnsoriginating from a plurality of yarn packages rotatably mounted aboutthe extrusion die, so that said weft yarns will contact said warpfilaments while they are still in plastic condition;

(e) simultaneously spacing said weft yarns so that they will enter intoconsecutive notches of the serrated strips; and

(f) laminating and consolidating the obtained construction by passing itthrough a pair of cooled pressure rolls.

2. Method according to claim 1, in which prior to lamination andconsolidation, and while the warp filaments are still in plasticcondition, the construction is superimposed, on at least one sidethereof, with a staple fiber web, whereby a multicomponent nonwovenfabric with an even fibrous texture on at least one side thereof isobtained.

3. Method according to claim 1, in which the Warp filaments are made ofa. thermoplastic resin.

4. Method according to claim 1, in which stretching of the warpfilaments is caused by driving the pressure rolls at a higher speed thanthe rate of filament extrusion.

5. Method according to claim 1, in which the serrated strips are made ofthermoplastic material.

6. Method according to claim 1, in which the weft yarns are staple fiberyarns.

7. Method according to claim 1, in which the weft yarns are filamentyarns.

8. Apparatus for making a multicomponent nonwoven fabric comprising incombination:

(a) means for extruding a curtain of resinous warp filaments along aconstructional path;

(b) weft layer means close to said constructional path for helicallywinding a plurality of continuous and properly spaced weft yarns aroundsaid warp curtain to form a multicomponent warp-weft construction; and

(c) a pair of pick-up pressure rolls at the end of said path, driven ata higher speed than the extrusion rate of warp filaments so as tostretch said filaments in order to cause proper orientation of the resinmolecules, said rolls also being adapted to laminate and consolidate thenonwoven construction.

9. Apparatus for making a multicomponent nonwoven fabric comprising incombination:

(a) an extruder with an extrusion die provided with a plurality ofaligned orifices and adapted to extrude a curtain of warp filaments;

(b) a frame rotatable about said extruder and containing a plurality ofWeft yarn supply packages, and means for rotating said frame;

(c) means for conveying a narrow strip with a serrated outer edge ateach side of the curtain of warp filaments;

(d) a spacing and laying member cooperating with said frame and adaptedto lay a plurality of Weft yarns, originating from the weft yarn supplypackages, in a properly spaced relationship and so that they will behelically wound around the curtain of warp filaments, bound by theserrated strips, when the frame is rotated, to form a multicomponentwarp-weft construction;

(e) a pair of pick-up pressure rolls positioned below the extruder dieand adapted to laminate and consolidate said warp-weft construction; and

(f) means for driving said pressure rolls at a desired higher speed thanthe rate of extrusion of the warp filaments so as to stretch the warpfilaments and cause proper orientation of the resin molecules.

10. Apparatus according to claim 9, in which the extrusion die isprovided with two extending plates having a guiding channel at each sidefor each serrated strip, said plates being adapted to provide adequatesupport for and to help proper forward movement of the helically woundweft yarns.

11. Apparatus according to claim 8, further comprising means forsuperimposing upon the warp-weft construction, on at least one sidethereof, a web of staple fibers. 12. Apparatus according to claim 8,further comprising means for cooling the pick-up pressure rolls.

13. Apparatus according to claim 9, further comprising means forsuperimposing upon the warp-weft construction, on at least one sidethereof, a Web of staple fibers.

14. Apparatus according to claim 9, further comprising means for coolingthe pick-up pressure rolls.

References Cited UNITED STATES PATENTS 3,041,230 6/1962 Diehl 1561722,847,056 8/1958 Vanlaer 156-172 XR 3,031,360 4/1962 Currier 156-167FOREIGN PATENTS 880,236 10/ 1961 Great Britain.

PHILIP DIER, Primary Examiner.

US. Cl. X.R.

